// Copyright (C) Kumo inc. and its affiliates.
// Author: Jeff.li lijippy@163.com
// All rights reserved.
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.
//

#pragma once

#include <cstdint>
#include <memory>
#include <string>
#include <string_view>
#include <unordered_map>
#include <utility>
#include <vector>


#include <turbo/utility/status.h>
#include <turbo/base/macros.h>

namespace nebula {

/// \brief A container for key-value pair type metadata. Not thread-safe
class TURBO_EXPORT KeyValueMetadata {
 public:
  KeyValueMetadata();
  KeyValueMetadata(std::vector<std::string> keys, std::vector<std::string> values);
  explicit KeyValueMetadata(const std::unordered_map<std::string, std::string>& map);

  static std::shared_ptr<KeyValueMetadata> create(std::vector<std::string> keys,
                                                std::vector<std::string> values);

  void ToUnorderedMap(std::unordered_map<std::string, std::string>* out) const;
  void append(std::string key, std::string value);

  turbo::Result<std::string> Get(std::string_view key) const;
  bool Contains(std::string_view key) const;
  // Note that deleting may invalidate known indices
  turbo::Status Delete(std::string_view key);
  turbo::Status Delete(int64_t index);
  turbo::Status DeleteMany(std::vector<int64_t> indices);
  turbo::Status Set(std::string key, std::string value);

  void reserve(int64_t n);

  int64_t size() const;
  const std::string& key(int64_t i) const;
  const std::string& value(int64_t i) const;
  const std::vector<std::string>& keys() const { return keys_; }
  const std::vector<std::string>& values() const { return values_; }

  std::vector<std::pair<std::string, std::string>> sorted_pairs() const;

  /// \brief Perform linear search for key, returning -1 if not found
  int FindKey(std::string_view key) const;

  std::shared_ptr<KeyValueMetadata> copy() const;

  /// \brief Return a new KeyValueMetadata by combining the passed metadata
  /// with this KeyValueMetadata. Colliding keys will be overridden by the
  /// passed metadata. Assumes keys in both containers are unique
  std::shared_ptr<KeyValueMetadata> Merge(const KeyValueMetadata& other) const;

  bool equals(const KeyValueMetadata& other) const;
  std::string to_string() const;

 private:
  std::vector<std::string> keys_;
  std::vector<std::string> values_;

  TURBO_DISALLOW_COPY_AND_ASSIGN(KeyValueMetadata);
};

/// \brief create a KeyValueMetadata instance
///
/// \param pairs key-value mapping
TURBO_EXPORT std::shared_ptr<KeyValueMetadata> key_value_metadata(
    const std::unordered_map<std::string, std::string>& pairs);

/// \brief create a KeyValueMetadata instance
///
/// \param keys sequence of metadata keys
/// \param values sequence of corresponding metadata values
TURBO_EXPORT std::shared_ptr<KeyValueMetadata> key_value_metadata(
    std::vector<std::string> keys, std::vector<std::string> values);

}  // namespace nebula
